/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 1999-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: DTMDefaultBase.java,v 1.3 2005/09/28 13:48:52 pvedula Exp $
 */
package com.sun.org.apache.xml.internal.dtm.ref;

import com.sun.org.apache.xml.internal.dtm.*;
import com.sun.org.apache.xml.internal.utils.SuballocatedIntVector;
import com.sun.org.apache.xml.internal.utils.BoolStack;

import java.util.Vector;

import javax.xml.transform.Source;

import com.sun.org.apache.xml.internal.utils.XMLString;
import com.sun.org.apache.xml.internal.utils.XMLStringFactory;

import com.sun.org.apache.xml.internal.res.XMLMessages;
import com.sun.org.apache.xml.internal.res.XMLErrorResources;

import java.io.*; // for dumpDTM

/**
 * The <code>DTMDefaultBase</code> class serves as a helper base for DTMs.
 * It sets up structures for navigation and type, while leaving data
 * management and construction to the derived classes.
 */
public abstract class DTMDefaultBase implements DTM {

  static final boolean JJK_DEBUG = false;

  // This constant is likely to be removed in the future. Use the
  // getDocument() method instead of ROOTNODE to get at the root
  // node of a DTM.
  /**
   * The identity of the root node.
   */
  public static final int ROOTNODE = 0;

  /**
   * The number of nodes, which is also used to determine the next
   * node index.
   */
  protected int m_size = 0;

  /**
   * The expanded names, one array element for each node.
   */
  protected SuballocatedIntVector m_exptype;

  /**
   * First child values, one array element for each node.
   */
  protected SuballocatedIntVector m_firstch;

  /**
   * Next sibling values, one array element for each node.
   */
  protected SuballocatedIntVector m_nextsib;

  /**
   * Previous sibling values, one array element for each node.
   */
  protected SuballocatedIntVector m_prevsib;

  /**
   * Previous sibling values, one array element for each node.
   */
  protected SuballocatedIntVector m_parent;

  /**
   * Vector of SuballocatedIntVectors of NS decl sets
   */
  protected Vector m_namespaceDeclSets = null;

  /**
   * SuballocatedIntVector  of elements at which corresponding
   * namespaceDeclSets were defined
   */
  protected SuballocatedIntVector m_namespaceDeclSetElements = null;

  /**
   * These hold indexes to elements based on namespace and local name.
   * The base lookup is the the namespace.  The second lookup is the local
   * name, and the last array contains the the first free element
   * at the start, and the list of element handles following.
   */
  protected int[][][] m_elemIndexes;

  /**
   * The default block size of the node arrays
   */
  public static final int DEFAULT_BLOCKSIZE = 512;  // favor small docs.

  /**
   * The number of blocks for the node arrays
   */
  public static final int DEFAULT_NUMBLOCKS = 32;

  /**
   * The number of blocks used for small documents & RTFs
   */
  public static final int DEFAULT_NUMBLOCKS_SMALL = 4;

  /** The block size of the node arrays */
  //protected final int m_blocksize;

  /**
   * The value to use when the information has not been built yet.
   */
  protected static final int NOTPROCESSED = DTM.NULL - 1;

  /**
   * The DTM manager who "owns" this DTM.
   */

  public DTMManager m_mgr;

  /**
   * m_mgr cast to DTMManagerDefault, or null if it isn't an instance
   * (Efficiency hook)
   */
  protected DTMManagerDefault m_mgrDefault = null;


  /**
   * The document identity number(s). If we have overflowed the addressing
   * range of the first that was assigned to us, we may add others.
   */
  protected SuballocatedIntVector m_dtmIdent;

  /** The mask for the identity.
   %REVIEW% Should this really be set to the _DEFAULT? What if
   a particular DTM wanted to use another value? */
  //protected final static int m_mask = DTMManager.IDENT_NODE_DEFAULT;

  /**
   * The base URI for this document.
   */
  protected String m_documentBaseURI;

  /**
   * The whitespace filter that enables elements to strip whitespace or not.
   */
  protected DTMWSFilter m_wsfilter;

  /**
   * Flag indicating whether to strip whitespace nodes
   */
  protected boolean m_shouldStripWS = false;

  /**
   * Stack of flags indicating whether to strip whitespace nodes
   */
  protected BoolStack m_shouldStripWhitespaceStack;

  /**
   * The XMLString factory for creating XMLStrings.
   */
  protected XMLStringFactory m_xstrf;

  /**
   * The table for exandedNameID lookups.  This may or may not be the same
   * table as is contained in the DTMManagerDefault.
   */
  protected ExpandedNameTable m_expandedNameTable;

  /**
   * true if indexing is turned on.
   */
  protected boolean m_indexing;

  /**
   * Construct a DTMDefaultBase object using the default block size.
   *
   * @param mgr The DTMManager who owns this DTM.
   * @param source The object that is used to specify the construction source.
   * @param dtmIdentity The DTM identity ID for this DTM.
   * @param whiteSpaceFilter The white space filter for this DTM, which may be null.
   * @param xstringfactory The factory to use for creating XMLStrings.
   * @param doIndexing true if the caller considers it worth it to use indexing schemes.
   */
  public DTMDefaultBase(DTMManager mgr, Source source, int dtmIdentity,
      DTMWSFilter whiteSpaceFilter,
      XMLStringFactory xstringfactory, boolean doIndexing) {
    this(mgr, source, dtmIdentity, whiteSpaceFilter, xstringfactory,
        doIndexing, DEFAULT_BLOCKSIZE, true, false);
  }

  /**
   * Construct a DTMDefaultBase object from a DOM node.
   *
   * @param mgr The DTMManager who owns this DTM.
   * @param source The object that is used to specify the construction source.
   * @param dtmIdentity The DTM identity ID for this DTM.
   * @param whiteSpaceFilter The white space filter for this DTM, which may be null.
   * @param xstringfactory The factory to use for creating XMLStrings.
   * @param doIndexing true if the caller considers it worth it to use indexing schemes.
   * @param blocksize The block size of the DTM.
   * @param usePrevsib true if we want to build the previous sibling node array.
   * @param newNameTable true if we want to use a new ExpandedNameTable for this DTM.
   */
  public DTMDefaultBase(DTMManager mgr, Source source, int dtmIdentity,
      DTMWSFilter whiteSpaceFilter,
      XMLStringFactory xstringfactory, boolean doIndexing,
      int blocksize, boolean usePrevsib,
      boolean newNameTable) {
    // Use smaller sizes for the internal node arrays if the block size
    // is small.
    int numblocks;
    if (blocksize <= 64) {
      numblocks = DEFAULT_NUMBLOCKS_SMALL;
      m_dtmIdent = new SuballocatedIntVector(4, 1);
    } else {
      numblocks = DEFAULT_NUMBLOCKS;
      m_dtmIdent = new SuballocatedIntVector(32);
    }

    m_exptype = new SuballocatedIntVector(blocksize, numblocks);
    m_firstch = new SuballocatedIntVector(blocksize, numblocks);
    m_nextsib = new SuballocatedIntVector(blocksize, numblocks);
    m_parent = new SuballocatedIntVector(blocksize, numblocks);

    // Only create the m_prevsib array if the usePrevsib flag is true.
    // Some DTM implementations (e.g. SAXImpl) do not need this array.
    // We can save the time to build it in those cases.
    if (usePrevsib) {
      m_prevsib = new SuballocatedIntVector(blocksize, numblocks);
    }

    m_mgr = mgr;
    if (mgr instanceof DTMManagerDefault) {
      m_mgrDefault = (DTMManagerDefault) mgr;
    }

    m_documentBaseURI = (null != source) ? source.getSystemId() : null;
    m_dtmIdent.setElementAt(dtmIdentity, 0);
    m_wsfilter = whiteSpaceFilter;
    m_xstrf = xstringfactory;
    m_indexing = doIndexing;

    if (doIndexing) {
      m_expandedNameTable = new ExpandedNameTable();
    } else {
      // Note that this fails if we aren't talking to an instance of
      // DTMManagerDefault
      m_expandedNameTable = m_mgrDefault.getExpandedNameTable(this);
    }

    if (null != whiteSpaceFilter) {
      m_shouldStripWhitespaceStack = new BoolStack();

      pushShouldStripWhitespace(false);
    }
  }

  /**
   * Ensure that the size of the element indexes can hold the information.
   *
   * @param namespaceID Namespace ID index.
   * @param LocalNameID Local name ID.
   */
  protected void ensureSizeOfIndex(int namespaceID, int LocalNameID) {

    if (null == m_elemIndexes) {
      m_elemIndexes = new int[namespaceID + 20][][];
    } else if (m_elemIndexes.length <= namespaceID) {
      int[][][] indexes = m_elemIndexes;

      m_elemIndexes = new int[namespaceID + 20][][];

      System.arraycopy(indexes, 0, m_elemIndexes, 0, indexes.length);
    }

    int[][] localNameIndex = m_elemIndexes[namespaceID];

    if (null == localNameIndex) {
      localNameIndex = new int[LocalNameID + 100][];
      m_elemIndexes[namespaceID] = localNameIndex;
    } else if (localNameIndex.length <= LocalNameID) {
      int[][] indexes = localNameIndex;

      localNameIndex = new int[LocalNameID + 100][];

      System.arraycopy(indexes, 0, localNameIndex, 0, indexes.length);

      m_elemIndexes[namespaceID] = localNameIndex;
    }

    int[] elemHandles = localNameIndex[LocalNameID];

    if (null == elemHandles) {
      elemHandles = new int[128];
      localNameIndex[LocalNameID] = elemHandles;
      elemHandles[0] = 1;
    } else if (elemHandles.length <= elemHandles[0] + 1) {
      int[] indexes = elemHandles;

      elemHandles = new int[elemHandles[0] + 1024];

      System.arraycopy(indexes, 0, elemHandles, 0, indexes.length);

      localNameIndex[LocalNameID] = elemHandles;
    }
  }

  /**
   * Add a node to the element indexes. The node will not be added unless
   * it's an element.
   *
   * @param expandedTypeID The expanded type ID of the node.
   * @param identity The node identity index.
   */
  protected void indexNode(int expandedTypeID, int identity) {

    ExpandedNameTable ent = m_expandedNameTable;
    short type = ent.getType(expandedTypeID);

    if (DTM.ELEMENT_NODE == type) {
      int namespaceID = ent.getNamespaceID(expandedTypeID);
      int localNameID = ent.getLocalNameID(expandedTypeID);

      ensureSizeOfIndex(namespaceID, localNameID);

      int[] index = m_elemIndexes[namespaceID][localNameID];

      index[index[0]] = identity;

      index[0]++;
    }
  }

  /**
   * Find the first index that occurs in the list that is greater than or
   * equal to the given value.
   *
   * @param list A list of integers.
   * @param start The start index to begin the search.
   * @param len The number of items to search.
   * @param value Find the slot that has a value that is greater than or identical to this
   * argument.
   * @return The index in the list of the slot that is higher or identical to the identity argument,
   * or -1 if no node is higher or equal.
   */
  protected int findGTE(int[] list, int start, int len, int value) {

    int low = start;
    int high = start + (len - 1);
    int end = high;

    while (low <= high) {
      int mid = (low + high) / 2;
      int c = list[mid];

      if (c > value) {
        high = mid - 1;
      } else if (c < value) {
        low = mid + 1;
      } else {
        return mid;
      }
    }

    return (low <= end && list[low] > value) ? low : -1;
  }

  /**
   * Find the first matching element from the index at or after the
   * given node.
   *
   * @param nsIndex The namespace index lookup.
   * @param lnIndex The local name index lookup.
   * @param firstPotential The first potential match that is worth looking at.
   * @return The first node that is greater than or equal to the firstPotential argument, or
   * DTM.NOTPROCESSED if not found.
   */
  int findElementFromIndex(int nsIndex, int lnIndex, int firstPotential) {

    int[][][] indexes = m_elemIndexes;

    if (null != indexes && nsIndex < indexes.length) {
      int[][] lnIndexs = indexes[nsIndex];

      if (null != lnIndexs && lnIndex < lnIndexs.length) {
        int[] elems = lnIndexs[lnIndex];

        if (null != elems) {
          int pos = findGTE(elems, 1, elems[0], firstPotential);

          if (pos > -1) {
            return elems[pos];
          }
        }
      }
    }

    return NOTPROCESSED;
  }

  /**
   * Get the next node identity value in the list, and call the iterator
   * if it hasn't been added yet.
   *
   * @param identity The node identity (index).
   * @return identity+1, or DTM.NULL.
   */
  protected abstract int getNextNodeIdentity(int identity);

  /**
   * This method should try and build one or more nodes in the table.
   *
   * @return The true if a next node is found or false if there are no more nodes.
   */
  protected abstract boolean nextNode();

  /**
   * Get the number of nodes that have been added.
   *
   * @return the number of nodes that have been mapped.
   */
  protected abstract int getNumberOfNodes();

  /**
   * Stateless axis traversers, lazely built.
   */
  protected DTMAxisTraverser[] m_traversers;

//    /**
//     * Ensure that the size of the information arrays can hold another entry
//     * at the given index.
//     *
//     * @param index On exit from this function, the information arrays sizes must be
//     * at least index+1.
//     */
//    protected void ensureSize(int index)
//    {
//        // We've cut over to Suballocated*Vector, which are self-sizing.
//    }

  /**
   * Get the simple type ID for the given node identity.
   *
   * @param identity The node identity.
   * @return The simple type ID, or DTM.NULL.
   */
  protected short _type(int identity) {

    int info = _exptype(identity);

    if (NULL != info) {
      return m_expandedNameTable.getType(info);
    } else {
      return NULL;
    }
  }

  /**
   * Get the expanded type ID for the given node identity.
   *
   * @param identity The node identity.
   * @return The expanded type ID, or DTM.NULL.
   */
  protected int _exptype(int identity) {
    if (identity == DTM.NULL) {
      return NULL;
    }
    // Reorganized test and loop into single flow
    // Tiny performance improvement, saves a few bytes of code, clearer.
    // %OPT% Other internal getters could be treated simliarly
    while (identity >= m_size) {
      if (!nextNode() && identity >= m_size) {
        return NULL;
      }
    }
    return m_exptype.elementAt(identity);

  }

  /**
   * Get the level in the tree for the given node identity.
   *
   * @param identity The node identity.
   * @return The tree level, or DTM.NULL.
   */
  protected int _level(int identity) {
    while (identity >= m_size) {
      boolean isMore = nextNode();
      if (!isMore && identity >= m_size) {
        return NULL;
      }
    }

    int i = 0;
    while (NULL != (identity = _parent(identity))) {
      ++i;
    }
    return i;
  }

  /**
   * Get the first child for the given node identity.
   *
   * @param identity The node identity.
   * @return The first child identity, or DTM.NULL.
   */
  protected int _firstch(int identity) {

    // Boiler-plate code for each of the _xxx functions, except for the array.
    int info = (identity >= m_size) ? NOTPROCESSED : m_firstch.elementAt(identity);

    // Check to see if the information requested has been processed, and,
    // if not, advance the iterator until we the information has been
    // processed.
    while (info == NOTPROCESSED) {
      boolean isMore = nextNode();

      if (identity >= m_size && !isMore) {
        return NULL;
      } else {
        info = m_firstch.elementAt(identity);
        if (info == NOTPROCESSED && !isMore) {
          return NULL;
        }
      }
    }

    return info;
  }

  /**
   * Get the next sibling for the given node identity.
   *
   * @param identity The node identity.
   * @return The next sibling identity, or DTM.NULL.
   */
  protected int _nextsib(int identity) {
    // Boiler-plate code for each of the _xxx functions, except for the array.
    int info = (identity >= m_size) ? NOTPROCESSED : m_nextsib.elementAt(identity);

    // Check to see if the information requested has been processed, and,
    // if not, advance the iterator until we the information has been
    // processed.
    while (info == NOTPROCESSED) {
      boolean isMore = nextNode();

      if (identity >= m_size && !isMore) {
        return NULL;
      } else {
        info = m_nextsib.elementAt(identity);
        if (info == NOTPROCESSED && !isMore) {
          return NULL;
        }
      }
    }

    return info;
  }

  /**
   * Get the previous sibling for the given node identity.
   *
   * @param identity The node identity.
   * @return The previous sibling identity, or DTM.NULL.
   */
  protected int _prevsib(int identity) {

    if (identity < m_size) {
      return m_prevsib.elementAt(identity);
    }

    // Check to see if the information requested has been processed, and,
    // if not, advance the iterator until we the information has been
    // processed.
    while (true) {
      boolean isMore = nextNode();

      if (identity >= m_size && !isMore) {
        return NULL;
      } else if (identity < m_size) {
        return m_prevsib.elementAt(identity);
      }
    }
  }

  /**
   * Get the parent for the given node identity.
   *
   * @param identity The node identity.
   * @return The parent identity, or DTM.NULL.
   */
  protected int _parent(int identity) {

    if (identity < m_size) {
      return m_parent.elementAt(identity);
    }

    // Check to see if the information requested has been processed, and,
    // if not, advance the iterator until we the information has been
    // processed.
    while (true) {
      boolean isMore = nextNode();

      if (identity >= m_size && !isMore) {
        return NULL;
      } else if (identity < m_size) {
        return m_parent.elementAt(identity);
      }
    }
  }

  /**
   * Diagnostics function to dump the DTM.
   */
  public void dumpDTM(OutputStream os) {
    try {
      if (os == null) {
        File f = new File("DTMDump" + ((Object) this).hashCode() + ".txt");
        System.err.println("Dumping... " + f.getAbsolutePath());
        os = new FileOutputStream(f);
      }
      PrintStream ps = new PrintStream(os);

      while (nextNode()) {
      }

      int nRecords = m_size;

      ps.println("Total nodes: " + nRecords);

      for (int index = 0; index < nRecords; ++index) {
        int i = makeNodeHandle(index);
        ps.println("=========== index=" + index + " handle=" + i + " ===========");
        ps.println("NodeName: " + getNodeName(i));
        ps.println("NodeNameX: " + getNodeNameX(i));
        ps.println("LocalName: " + getLocalName(i));
        ps.println("NamespaceURI: " + getNamespaceURI(i));
        ps.println("Prefix: " + getPrefix(i));

        int exTypeID = _exptype(index);

        ps.println("Expanded Type ID: "
            + Integer.toHexString(exTypeID));

        int type = _type(index);
        String typestring;

        switch (type) {
          case DTM.ATTRIBUTE_NODE:
            typestring = "ATTRIBUTE_NODE";
            break;
          case DTM.CDATA_SECTION_NODE:
            typestring = "CDATA_SECTION_NODE";
            break;
          case DTM.COMMENT_NODE:
            typestring = "COMMENT_NODE";
            break;
          case DTM.DOCUMENT_FRAGMENT_NODE:
            typestring = "DOCUMENT_FRAGMENT_NODE";
            break;
          case DTM.DOCUMENT_NODE:
            typestring = "DOCUMENT_NODE";
            break;
          case DTM.DOCUMENT_TYPE_NODE:
            typestring = "DOCUMENT_NODE";
            break;
          case DTM.ELEMENT_NODE:
            typestring = "ELEMENT_NODE";
            break;
          case DTM.ENTITY_NODE:
            typestring = "ENTITY_NODE";
            break;
          case DTM.ENTITY_REFERENCE_NODE:
            typestring = "ENTITY_REFERENCE_NODE";
            break;
          case DTM.NAMESPACE_NODE:
            typestring = "NAMESPACE_NODE";
            break;
          case DTM.NOTATION_NODE:
            typestring = "NOTATION_NODE";
            break;
          case DTM.NULL:
            typestring = "NULL";
            break;
          case DTM.PROCESSING_INSTRUCTION_NODE:
            typestring = "PROCESSING_INSTRUCTION_NODE";
            break;
          case DTM.TEXT_NODE:
            typestring = "TEXT_NODE";
            break;
          default:
            typestring = "Unknown!";
            break;
        }

        ps.println("Type: " + typestring);

        int firstChild = _firstch(index);

        if (DTM.NULL == firstChild) {
          ps.println("First child: DTM.NULL");
        } else if (NOTPROCESSED == firstChild) {
          ps.println("First child: NOTPROCESSED");
        } else {
          ps.println("First child: " + firstChild);
        }

        if (m_prevsib != null) {
          int prevSibling = _prevsib(index);

          if (DTM.NULL == prevSibling) {
            ps.println("Prev sibling: DTM.NULL");
          } else if (NOTPROCESSED == prevSibling) {
            ps.println("Prev sibling: NOTPROCESSED");
          } else {
            ps.println("Prev sibling: " + prevSibling);
          }
        }

        int nextSibling = _nextsib(index);

        if (DTM.NULL == nextSibling) {
          ps.println("Next sibling: DTM.NULL");
        } else if (NOTPROCESSED == nextSibling) {
          ps.println("Next sibling: NOTPROCESSED");
        } else {
          ps.println("Next sibling: " + nextSibling);
        }

        int parent = _parent(index);

        if (DTM.NULL == parent) {
          ps.println("Parent: DTM.NULL");
        } else if (NOTPROCESSED == parent) {
          ps.println("Parent: NOTPROCESSED");
        } else {
          ps.println("Parent: " + parent);
        }

        int level = _level(index);

        ps.println("Level: " + level);
        ps.println("Node Value: " + getNodeValue(i));
        ps.println("String Value: " + getStringValue(i));
      }
    } catch (IOException ioe) {
      ioe.printStackTrace(System.err);
      throw new RuntimeException(ioe.getMessage());
    }
  }

  /**
   * Diagnostics function to dump a single node.
   *
   * %REVIEW% KNOWN GLITCH: If you pass it a node index rather than a
   * node handle, it works just fine... but the displayed identity
   * number before the colon is different, which complicates comparing
   * it with nodes printed the other way. We could always OR the DTM ID
   * into the value, to suppress that distinction...
   *
   * %REVIEW% This might want to be moved up to DTMDefaultBase, or possibly
   * DTM itself, since it's a useful diagnostic and uses only DTM's public
   * APIs.
   */
  public String dumpNode(int nodeHandle) {
    if (nodeHandle == DTM.NULL) {
      return "[null]";
    }

    String typestring;
    switch (getNodeType(nodeHandle)) {
      case DTM.ATTRIBUTE_NODE:
        typestring = "ATTR";
        break;
      case DTM.CDATA_SECTION_NODE:
        typestring = "CDATA";
        break;
      case DTM.COMMENT_NODE:
        typestring = "COMMENT";
        break;
      case DTM.DOCUMENT_FRAGMENT_NODE:
        typestring = "DOC_FRAG";
        break;
      case DTM.DOCUMENT_NODE:
        typestring = "DOC";
        break;
      case DTM.DOCUMENT_TYPE_NODE:
        typestring = "DOC_TYPE";
        break;
      case DTM.ELEMENT_NODE:
        typestring = "ELEMENT";
        break;
      case DTM.ENTITY_NODE:
        typestring = "ENTITY";
        break;
      case DTM.ENTITY_REFERENCE_NODE:
        typestring = "ENT_REF";
        break;
      case DTM.NAMESPACE_NODE:
        typestring = "NAMESPACE";
        break;
      case DTM.NOTATION_NODE:
        typestring = "NOTATION";
        break;
      case DTM.NULL:
        typestring = "null";
        break;
      case DTM.PROCESSING_INSTRUCTION_NODE:
        typestring = "PI";
        break;
      case DTM.TEXT_NODE:
        typestring = "TEXT";
        break;
      default:
        typestring = "Unknown!";
        break;
    }

    return "[" + nodeHandle + ": " + typestring +
        "(0x" + Integer.toHexString(getExpandedTypeID(nodeHandle)) + ") " +
        getNodeNameX(nodeHandle) + " {" + getNamespaceURI(nodeHandle) + "}" +
        "=\"" + getNodeValue(nodeHandle) + "\"]";
  }

  // ========= DTM Implementation Control Functions. ==============

  /**
   * Set an implementation dependent feature.
   * <p>
   * %REVIEW% Do we really expect to set features on DTMs?
   *
   * @param featureId A feature URL.
   * @param state true if this feature should be on, false otherwise.
   */
  public void setFeature(String featureId, boolean state) {
  }

  // ========= Document Navigation Functions =========

  /**
   * Given a node handle, test if it has child nodes.
   * <p> %REVIEW% This is obviously useful at the DOM layer, where it
   * would permit testing this without having to create a proxy
   * node. It's less useful in the DTM API, where
   * (dtm.getFirstChild(nodeHandle)!=DTM.NULL) is just as fast and
   * almost as self-evident. But it's a convenience, and eases porting
   * of DOM code to DTM.  </p>
   *
   * @param nodeHandle int Handle of the node.
   * @return int true if the given node has child nodes.
   */
  public boolean hasChildNodes(int nodeHandle) {

    int identity = makeNodeIdentity(nodeHandle);
    int firstChild = _firstch(identity);

    return firstChild != DTM.NULL;
  }

  /**
   * Given a node identity, return a node handle. If extended addressing
   * has been used (multiple DTM IDs), we need to map the high bits of the
   * identity into the proper DTM ID.
   *
   * This has been made FINAL to facilitate inlining, since we do not expect
   * any subclass of DTMDefaultBase to ever change the algorithm. (I don't
   * really like doing so, and would love to have an excuse not to...)
   *
   * %REVIEW% Is it worth trying to specialcase small documents?
   * %REVIEW% Should this be exposed at the package/public layers?
   *
   * @param nodeIdentity Internal offset to this node's records.
   * @return NodeHandle (external representation of node)
   */
  final public int makeNodeHandle(int nodeIdentity) {
    if (NULL == nodeIdentity) {
      return NULL;
    }

    if (JJK_DEBUG && nodeIdentity > DTMManager.IDENT_NODE_DEFAULT) {
      System.err.println("GONK! (only useful in limited situations)");
    }

    return m_dtmIdent.elementAt(nodeIdentity >>> DTMManager.IDENT_DTM_NODE_BITS)
        + (nodeIdentity & DTMManager.IDENT_NODE_DEFAULT);
  }

  /**
   * Given a node handle, return a node identity. If extended addressing
   * has been used (multiple DTM IDs), we need to map the high bits of the
   * identity into the proper DTM ID and thence find the proper offset
   * to add to the low bits of the identity
   *
   * This has been made FINAL to facilitate inlining, since we do not expect
   * any subclass of DTMDefaultBase to ever change the algorithm. (I don't
   * really like doing so, and would love to have an excuse not to...)
   *
   * %OPT% Performance is critical for this operation.
   *
   * %REVIEW% Should this be exposed at the package/public layers?
   *
   * @param nodeHandle (external representation of node)
   * @return nodeIdentity Internal offset to this node's records.
   */
  final public int makeNodeIdentity(int nodeHandle) {
    if (NULL == nodeHandle) {
      return NULL;
    }

    if (m_mgrDefault != null) {
      // Optimization: use the DTMManagerDefault's fast DTMID-to-offsets
      // table.  I'm not wild about this solution but this operation
      // needs need extreme speed.

      int whichDTMindex = nodeHandle >>> DTMManager.IDENT_DTM_NODE_BITS;

      // %REVIEW% Wish I didn't have to perform the pre-test, but
      // someone is apparently asking DTMs whether they contain nodes
      // which really don't belong to them. That's probably a bug
      // which should be fixed, but until it is:
      if (m_mgrDefault.m_dtms[whichDTMindex] != this) {
        return NULL;
      } else {
        return
            m_mgrDefault.m_dtm_offsets[whichDTMindex]
                | (nodeHandle & DTMManager.IDENT_NODE_DEFAULT);
      }
    }

    int whichDTMid = m_dtmIdent.indexOf(nodeHandle & DTMManager.IDENT_DTM_DEFAULT);
    return (whichDTMid == NULL)
        ? NULL
        : (whichDTMid << DTMManager.IDENT_DTM_NODE_BITS)
            + (nodeHandle & DTMManager.IDENT_NODE_DEFAULT);
  }


  /**
   * Given a node handle, get the handle of the node's first child.
   * If not yet resolved, waits for more nodes to be added to the document and
   * tries again.
   *
   * @param nodeHandle int Handle of the node.
   * @return int DTM node-number of first child, or DTM.NULL to indicate none exists.
   */
  public int getFirstChild(int nodeHandle) {

    int identity = makeNodeIdentity(nodeHandle);
    int firstChild = _firstch(identity);

    return makeNodeHandle(firstChild);
  }

  /**
   * Given a node handle, get the handle of the node's first child.
   * If not yet resolved, waits for more nodes to be added to the document and
   * tries again.
   *
   * @param nodeHandle int Handle of the node.
   * @return int DTM node-number of first child, or DTM.NULL to indicate none exists.
   */
  public int getTypedFirstChild(int nodeHandle, int nodeType) {

    int firstChild, eType;
    if (nodeType < DTM.NTYPES) {
      for (firstChild = _firstch(makeNodeIdentity(nodeHandle));
          firstChild != DTM.NULL;
          firstChild = _nextsib(firstChild)) {
        eType = _exptype(firstChild);
        if (eType == nodeType
            || (eType >= DTM.NTYPES
            && m_expandedNameTable.getType(eType) == nodeType)) {
          return makeNodeHandle(firstChild);
        }
      }
    } else {
      for (firstChild = _firstch(makeNodeIdentity(nodeHandle));
          firstChild != DTM.NULL;
          firstChild = _nextsib(firstChild)) {
        if (_exptype(firstChild) == nodeType) {
          return makeNodeHandle(firstChild);
        }
      }
    }
    return DTM.NULL;
  }

  /**
   * Given a node handle, advance to its last child.
   * If not yet resolved, waits for more nodes to be added to the document and
   * tries again.
   *
   * @param nodeHandle int Handle of the node.
   * @return int Node-number of last child, or DTM.NULL to indicate none exists.
   */
  public int getLastChild(int nodeHandle) {

    int identity = makeNodeIdentity(nodeHandle);
    int child = _firstch(identity);
    int lastChild = DTM.NULL;

    while (child != DTM.NULL) {
      lastChild = child;
      child = _nextsib(child);
    }

    return makeNodeHandle(lastChild);
  }

  /**
   * Retrieves an attribute node by by qualified name and namespace URI.
   *
   * @param nodeHandle int Handle of the node upon which to look up this attribute..
   * @param namespaceURI The namespace URI of the attribute to retrieve, or null.
   * @param name The local name of the attribute to retrieve.
   * @return The attribute node handle with the specified name ( <code>nodeName</code>) or
   * <code>DTM.NULL</code> if there is no such attribute.
   */
  public abstract int getAttributeNode(int nodeHandle, String namespaceURI,
      String name);

  /**
   * Given a node handle, get the index of the node's first attribute.
   *
   * @param nodeHandle int Handle of the node.
   * @return Handle of first attribute, or DTM.NULL to indicate none exists.
   */
  public int getFirstAttribute(int nodeHandle) {
    int nodeID = makeNodeIdentity(nodeHandle);

    return makeNodeHandle(getFirstAttributeIdentity(nodeID));
  }

  /**
   * Given a node identity, get the index of the node's first attribute.
   *
   * @param identity int identity of the node.
   * @return Identity of first attribute, or DTM.NULL to indicate none exists.
   */
  protected int getFirstAttributeIdentity(int identity) {
    int type = _type(identity);

    if (DTM.ELEMENT_NODE == type) {
      // Assume that attributes and namespaces immediately follow the element.
      while (DTM.NULL != (identity = getNextNodeIdentity(identity))) {

        // Assume this can not be null.
        type = _type(identity);

        if (type == DTM.ATTRIBUTE_NODE) {
          return identity;
        } else if (DTM.NAMESPACE_NODE != type) {
          break;
        }
      }
    }

    return DTM.NULL;
  }

  /**
   * Given a node handle and an expanded type ID, get the index of the node's
   * attribute of that type, if any.
   *
   * @param nodeHandle int Handle of the node.
   * @param attType int expanded type ID of the required attribute.
   * @return Handle of attribute of the required type, or DTM.NULL to indicate none exists.
   */
  protected int getTypedAttribute(int nodeHandle, int attType) {
    int type = getNodeType(nodeHandle);
    if (DTM.ELEMENT_NODE == type) {
      int identity = makeNodeIdentity(nodeHandle);

      while (DTM.NULL != (identity = getNextNodeIdentity(identity))) {
        type = _type(identity);

        if (type == DTM.ATTRIBUTE_NODE) {
          if (_exptype(identity) == attType) {
            return makeNodeHandle(identity);
          }
        } else if (DTM.NAMESPACE_NODE != type) {
          break;
        }
      }
    }

    return DTM.NULL;
  }

  /**
   * Given a node handle, advance to its next sibling.
   * If not yet resolved, waits for more nodes to be added to the document and
   * tries again.
   *
   * @param nodeHandle int Handle of the node.
   * @return int Node-number of next sibling, or DTM.NULL to indicate none exists.
   */
  public int getNextSibling(int nodeHandle) {
    if (nodeHandle == DTM.NULL) {
      return DTM.NULL;
    }
    return makeNodeHandle(_nextsib(makeNodeIdentity(nodeHandle)));
  }

  /**
   * Given a node handle, advance to its next sibling.
   * If not yet resolved, waits for more nodes to be added to the document and
   * tries again.
   *
   * @param nodeHandle int Handle of the node.
   * @return int Node-number of next sibling, or DTM.NULL to indicate none exists.
   */
  public int getTypedNextSibling(int nodeHandle, int nodeType) {
    if (nodeHandle == DTM.NULL) {
      return DTM.NULL;
    }
    int node = makeNodeIdentity(nodeHandle);
    int eType;
    while ((node = _nextsib(node)) != DTM.NULL &&
        ((eType = _exptype(node)) != nodeType &&
            m_expandedNameTable.getType(eType) != nodeType)) {
      ;
    }
    //_type(node) != nodeType));

    return (node == DTM.NULL ? DTM.NULL : makeNodeHandle(node));
  }

  /**
   * Given a node handle, find its preceeding sibling.
   * WARNING: DTM is asymmetric; this operation is resolved by search, and is
   * relatively expensive.
   *
   * @param nodeHandle the id of the node.
   * @return int Node-number of the previous sib, or DTM.NULL to indicate none exists.
   */
  public int getPreviousSibling(int nodeHandle) {
    if (nodeHandle == DTM.NULL) {
      return DTM.NULL;
    }

    if (m_prevsib != null) {
      return makeNodeHandle(_prevsib(makeNodeIdentity(nodeHandle)));
    } else {
      // If the previous sibling array is not built, we get at
      // the previous sibling using the parent, firstch and
      // nextsib arrays.
      int nodeID = makeNodeIdentity(nodeHandle);
      int parent = _parent(nodeID);
      int node = _firstch(parent);
      int result = DTM.NULL;
      while (node != nodeID) {
        result = node;
        node = _nextsib(node);
      }
      return makeNodeHandle(result);
    }
  }

  /**
   * Given a node handle, advance to the next attribute.
   * If an attr, we advance to
   * the next attr on the same node.  If not an attribute, we return NULL.
   *
   * @param nodeHandle int Handle of the node.
   * @return int DTM node-number of the resolved attr, or DTM.NULL to indicate none exists.
   */
  public int getNextAttribute(int nodeHandle) {
    int nodeID = makeNodeIdentity(nodeHandle);

    if (_type(nodeID) == DTM.ATTRIBUTE_NODE) {
      return makeNodeHandle(getNextAttributeIdentity(nodeID));
    }

    return DTM.NULL;
  }

  /**
   * Given a node identity for an attribute, advance to the next attribute.
   *
   * @param identity int identity of the attribute node.  This <strong>must</strong> be an attribute
   * node.
   * @return int DTM node-identity of the resolved attr, or DTM.NULL to indicate none exists.
   */
  protected int getNextAttributeIdentity(int identity) {
    // Assume that attributes and namespace nodes immediately follow the element
    while (DTM.NULL != (identity = getNextNodeIdentity(identity))) {
      int type = _type(identity);

      if (type == DTM.ATTRIBUTE_NODE) {
        return identity;
      } else if (type != DTM.NAMESPACE_NODE) {
        break;
      }
    }

    return DTM.NULL;
  }

  /**
   * Lazily created namespace lists.
   */
  private Vector m_namespaceLists = null;  // on demand


  /**
   * Build table of namespace declaration
   * locations during DTM construction. Table is a Vector of
   * SuballocatedIntVectors containing the namespace node HANDLES declared at
   * that ID, plus an SuballocatedIntVector of the element node INDEXES at which
   * these declarations appeared.
   *
   * NOTE: Since this occurs during model build, nodes will be encountered
   * in doucment order and thus the table will be ordered by element,
   * permitting binary-search as a possible retrieval optimization.
   *
   * %REVIEW% Directly managed arrays rather than vectors?
   * %REVIEW% Handles or IDs? Given usage, I think handles.
   */
  protected void declareNamespaceInContext(int elementNodeIndex, int namespaceNodeIndex) {
    SuballocatedIntVector nsList = null;
    if (m_namespaceDeclSets == null) {

      // First
      m_namespaceDeclSetElements = new SuballocatedIntVector(32);
      m_namespaceDeclSetElements.addElement(elementNodeIndex);
      m_namespaceDeclSets = new Vector();
      nsList = new SuballocatedIntVector(32);
      m_namespaceDeclSets.addElement(nsList);
    } else {
      // Most recent. May be -1 (none) if DTM was pruned.
      // %OPT% Is there a lastElement() method? Should there be?
      int last = m_namespaceDeclSetElements.size() - 1;

      if (last >= 0 && elementNodeIndex == m_namespaceDeclSetElements.elementAt(last)) {
        nsList = (SuballocatedIntVector) m_namespaceDeclSets.elementAt(last);
      }
    }
    if (nsList == null) {
      m_namespaceDeclSetElements.addElement(elementNodeIndex);

      SuballocatedIntVector inherited =
          findNamespaceContext(_parent(elementNodeIndex));

      if (inherited != null) {
        // %OPT% Count-down might be faster, but debuggability may
        // be better this way, and if we ever decide we want to
        // keep this ordered by expanded-type...
        int isize = inherited.size();

        // Base the size of a new namespace list on the
        // size of the inherited list - but within reason!
        nsList = new SuballocatedIntVector(Math.max(Math.min(isize + 16, 2048),
            32));

        for (int i = 0; i < isize; ++i) {
          nsList.addElement(inherited.elementAt(i));
        }
      } else {
        nsList = new SuballocatedIntVector(32);
      }

      m_namespaceDeclSets.addElement(nsList);
    }

    // Handle overwriting inherited.
    // %OPT% Keep sorted? (By expanded-name rather than by doc order...)
    // Downside: Would require insertElementAt if not found,
    // which has recopying costs. But these are generally short lists...
    int newEType = _exptype(namespaceNodeIndex);

    for (int i = nsList.size() - 1; i >= 0; --i) {
      if (newEType == getExpandedTypeID(nsList.elementAt(i))) {
        nsList.setElementAt(makeNodeHandle(namespaceNodeIndex), i);
        return;
      }
    }
    nsList.addElement(makeNodeHandle(namespaceNodeIndex));
  }

  /**
   * Retrieve list of namespace declaration locations
   * active at this node. List is an SuballocatedIntVector whose
   * entries are the namespace node HANDLES declared at that ID.
   *
   * %REVIEW% Directly managed arrays rather than vectors?
   * %REVIEW% Handles or IDs? Given usage, I think handles.
   */
  protected SuballocatedIntVector findNamespaceContext(int elementNodeIndex) {
    if (null != m_namespaceDeclSetElements) {
      // %OPT% Is binary-search really saving us a lot versus linear?
      // (... It may be, in large docs with many NS decls.)
      int wouldBeAt = findInSortedSuballocatedIntVector(m_namespaceDeclSetElements,
          elementNodeIndex);
      if (wouldBeAt >= 0) // Found it
      {
        return (SuballocatedIntVector) m_namespaceDeclSets.elementAt(wouldBeAt);
      }
      if (wouldBeAt == -1) // -1-wouldbeat == 0
      {
        return null; // Not after anything; definitely not found
      }

      // Not found, but we know where it should have been.
      // Search back until we find an ancestor or run out.
      wouldBeAt = -1 - wouldBeAt;

      // Decrement wouldBeAt to find last possible ancestor
      int candidate = m_namespaceDeclSetElements.elementAt(--wouldBeAt);
      int ancestor = _parent(elementNodeIndex);

      // Special case: if the candidate is before the given node, and
      // is in the earliest possible position in the document, it
      // must have the namespace declarations we're interested in.
      if (wouldBeAt == 0 && candidate < ancestor) {
        int rootHandle = getDocumentRoot(makeNodeHandle(elementNodeIndex));
        int rootID = makeNodeIdentity(rootHandle);
        int uppermostNSCandidateID;

        if (getNodeType(rootHandle) == DTM.DOCUMENT_NODE) {
          int ch = _firstch(rootID);
          uppermostNSCandidateID = (ch != DTM.NULL) ? ch : rootID;
        } else {
          uppermostNSCandidateID = rootID;
        }

        if (candidate == uppermostNSCandidateID) {
          return (SuballocatedIntVector) m_namespaceDeclSets.elementAt(wouldBeAt);
        }
      }

      while (wouldBeAt >= 0 && ancestor > 0) {
        if (candidate == ancestor) {
          // Found ancestor in list
          return (SuballocatedIntVector) m_namespaceDeclSets.elementAt(wouldBeAt);
        } else if (candidate < ancestor) {
          // Too deep in tree
          do {
            ancestor = _parent(ancestor);
          } while (candidate < ancestor);
        } else if (wouldBeAt > 0) {
          // Too late in list
          candidate = m_namespaceDeclSetElements.elementAt(--wouldBeAt);
        } else {
          break;
        }
      }
    }

    return null; // No namespaces known at this node
  }

  /**
   * Subroutine: Locate the specified node within
   * m_namespaceDeclSetElements, or the last element which
   * preceeds it in document order
   *
   * %REVIEW% Inlne this into findNamespaceContext? Create SortedSuballocatedIntVector type?
   *
   * @return If positive or zero, the index of the found item. If negative, index of the point at
   * which it would have appeared, encoded as -1-index and hence reconvertable by subtracting it
   * from -1. (Encoding because I don't want to recompare the strings but don't want to burn bytes
   * on a datatype to hold a flagged value.)
   */
  protected int findInSortedSuballocatedIntVector(SuballocatedIntVector vector, int lookfor) {
    // Binary search
    int i = 0;
    if (vector != null) {
      int first = 0;
      int last = vector.size() - 1;

      while (first <= last) {
        i = (first + last) / 2;
        int test = lookfor - vector.elementAt(i);
        if (test == 0) {
          return i; // Name found
        } else if (test < 0) {
          last = i - 1; // looked too late
        } else {
          first = i + 1; // looked ot early
        }
      }

      if (first > i) {
        i = first; // Clean up at loop end
      }
    }

    return -1 - i; // not-found has to be encoded.
  }


  /**
   * Given a node handle, get the index of the node's first child.
   * If not yet resolved, waits for more nodes to be added to the document and
   * tries again
   *
   * @param nodeHandle handle to node, which should probably be an element node, but need not be.
   * @param inScope true if all namespaces in scope should be returned, false if only the namespace
   * declarations should be returned.
   * @return handle of first namespace, or DTM.NULL to indicate none exists.
   */
  public int getFirstNamespaceNode(int nodeHandle, boolean inScope) {
    if (inScope) {
      int identity = makeNodeIdentity(nodeHandle);
      if (_type(identity) == DTM.ELEMENT_NODE) {
        SuballocatedIntVector nsContext = findNamespaceContext(identity);
        if (nsContext == null || nsContext.size() < 1) {
          return NULL;
        }

        return nsContext.elementAt(0);
      } else {
        return NULL;
      }
    } else {
      // Assume that attributes and namespaces immediately
      // follow the element.
      //
      // %OPT% Would things be faster if all NS nodes were built
      // before all Attr nodes? Some costs at build time for 2nd
      // pass...
      int identity = makeNodeIdentity(nodeHandle);
      if (_type(identity) == DTM.ELEMENT_NODE) {
        while (DTM.NULL != (identity = getNextNodeIdentity(identity))) {
          int type = _type(identity);
          if (type == DTM.NAMESPACE_NODE) {
            return makeNodeHandle(identity);
          } else if (DTM.ATTRIBUTE_NODE != type) {
            break;
          }
        }
        return NULL;
      } else {
        return NULL;
      }
    }
  }

  /**
   * Given a namespace handle, advance to the next namespace.
   *
   * @param baseHandle handle to original node from where the first namespace was relative to
   * (needed to return nodes in document order).
   * @param nodeHandle A namespace handle for which we will find the next node.
   * @param inScope true if all namespaces that are in scope should be processed, otherwise just
   * process the nodes in the given element handle.
   * @return handle of next namespace, or DTM.NULL to indicate none exists.
   */
  public int getNextNamespaceNode(int baseHandle, int nodeHandle,
      boolean inScope) {
    if (inScope) {
      //Since we've been given the base, try direct lookup
      //(could look from nodeHandle but this is at least one
      //comparison/get-parent faster)
      //SuballocatedIntVector nsContext=findNamespaceContext(nodeHandle & m_mask);

      SuballocatedIntVector nsContext = findNamespaceContext(makeNodeIdentity(baseHandle));

      if (nsContext == null) {
        return NULL;
      }
      int i = 1 + nsContext.indexOf(nodeHandle);
      if (i <= 0 || i == nsContext.size()) {
        return NULL;
      }

      return nsContext.elementAt(i);
    } else {
      // Assume that attributes and namespace nodes immediately follow the element.
      int identity = makeNodeIdentity(nodeHandle);
      while (DTM.NULL != (identity = getNextNodeIdentity(identity))) {
        int type = _type(identity);
        if (type == DTM.NAMESPACE_NODE) {
          return makeNodeHandle(identity);
        } else if (type != DTM.ATTRIBUTE_NODE) {
          break;
        }
      }
    }
    return DTM.NULL;
  }

  /**
   * Given a node handle, find its parent node.
   *
   * @param nodeHandle the id of the node.
   * @return int Node-number of parent, or DTM.NULL to indicate none exists.
   */
  public int getParent(int nodeHandle) {

    int identity = makeNodeIdentity(nodeHandle);

    if (identity > 0) {
      return makeNodeHandle(_parent(identity));
    } else {
      return DTM.NULL;
    }
  }

  /**
   * Find the Document node handle for the document currently under construction.
   * PLEASE NOTE that most people should use getOwnerDocument(nodeHandle) instead;
   * this version of the operation is primarily intended for use during negotiation
   * with the DTM Manager.
   *
   * @return int Node handle of document, which should always be valid.
   */
  public int getDocument() {
    return m_dtmIdent.elementAt(0); // makeNodeHandle(0)
  }

  /**
   * Given a node handle, find the owning document node.  This has the exact
   * same semantics as the DOM Document method of the same name, in that if
   * the nodeHandle is a document node, it will return NULL.
   *
   * <p>%REVIEW% Since this is DOM-specific, it may belong at the DOM
   * binding layer. Included here as a convenience function and to
   * aid porting of DOM code to DTM.</p>
   *
   * @param nodeHandle the id of the node.
   * @return int Node handle of owning document, or -1 if the node was a Docment
   */
  public int getOwnerDocument(int nodeHandle) {

    if (DTM.DOCUMENT_NODE == getNodeType(nodeHandle)) {
      return DTM.NULL;
    }

    return getDocumentRoot(nodeHandle);
  }

  /**
   * Given a node handle, find the owning document node.  Unlike the DOM,
   * this considers the owningDocument of a Document to be itself.
   *
   * @param nodeHandle the id of the node.
   * @return int Node handle of owning document, or the nodeHandle if it is a Document.
   */
  public int getDocumentRoot(int nodeHandle) {
    return getManager().getDTM(nodeHandle).getDocument();
  }

  /**
   * Get the string-value of a node as a String object
   * (see http://www.w3.org/TR/xpath#data-model
   * for the definition of a node's string-value).
   *
   * @param nodeHandle The node ID.
   * @return A string object that represents the string-value of the given node.
   */
  public abstract XMLString getStringValue(int nodeHandle);

  /**
   * Get number of character array chunks in
   * the string-value of a node.
   * (see http://www.w3.org/TR/xpath#data-model
   * for the definition of a node's string-value).
   * Note that a single text node may have multiple text chunks.
   *
   * @param nodeHandle The node ID.
   * @return number of character array chunks in the string-value of a node.
   */
  public int getStringValueChunkCount(int nodeHandle) {

    // %TBD%
    error(XMLMessages.createXMLMessage(XMLErrorResources.ER_METHOD_NOT_SUPPORTED,
        null));//("getStringValueChunkCount not yet supported!");

    return 0;
  }

  /**
   * Get a character array chunk in the string-value of a node.
   * (see http://www.w3.org/TR/xpath#data-model
   * for the definition of a node's string-value).
   * Note that a single text node may have multiple text chunks.
   *
   * @param nodeHandle The node ID.
   * @param chunkIndex Which chunk to get.
   * @param startAndLen An array of 2 where the start position and length of the chunk will be
   * returned.
   * @return The character array reference where the chunk occurs.
   */
  public char[] getStringValueChunk(int nodeHandle, int chunkIndex,
      int[] startAndLen) {

    // %TBD%
    error(XMLMessages.createXMLMessage(XMLErrorResources.ER_METHOD_NOT_SUPPORTED,
        null));//"getStringValueChunk not yet supported!");

    return null;
  }

  /**
   * Given a node handle, return an ID that represents the node's expanded name.
   *
   * @param nodeHandle The handle to the node in question.
   * @return the expanded-name id of the node.
   */
  public int getExpandedTypeID(int nodeHandle) {
    // %REVIEW% This _should_ only be null if someone asked the wrong DTM about the node...
    // which one would hope would never happen...
    int id = makeNodeIdentity(nodeHandle);
    if (id == NULL) {
      return NULL;
    }
    return _exptype(id);
  }

  /**
   * Given an expanded name, return an ID.  If the expanded-name does not
   * exist in the internal tables, the entry will be created, and the ID will
   * be returned.  Any additional nodes that are created that have this
   * expanded name will use this ID.
   *
   * @param type The simple type, i.e. one of ELEMENT, ATTRIBUTE, etc.
   * @param namespace The namespace URI, which may be null, may be an empty string (which will be
   * the same as null), or may be a namespace URI.
   * @param localName The local name string, which must be a valid <a
   * href="http://www.w3.org/TR/REC-xml-names/">NCName</a>.
   * @return the expanded-name id of the node.
   */
  public int getExpandedTypeID(String namespace, String localName, int type) {

    ExpandedNameTable ent = m_expandedNameTable;

    return ent.getExpandedTypeID(namespace, localName, type);
  }

  /**
   * Given an expanded-name ID, return the local name part.
   *
   * @param expandedNameID an ID that represents an expanded-name.
   * @return String Local name of this node.
   */
  public String getLocalNameFromExpandedNameID(int expandedNameID) {
    return m_expandedNameTable.getLocalName(expandedNameID);
  }

  /**
   * Given an expanded-name ID, return the namespace URI part.
   *
   * @param expandedNameID an ID that represents an expanded-name.
   * @return String URI value of this node's namespace, or null if no namespace was resolved.
   */
  public String getNamespaceFromExpandedNameID(int expandedNameID) {
    return m_expandedNameTable.getNamespace(expandedNameID);
  }

  /**
   * Returns the namespace type of a specific node
   *
   * @param nodeHandle the id of the node.
   * @return the ID of the namespace.
   */
  public int getNamespaceType(final int nodeHandle) {

    int identity = makeNodeIdentity(nodeHandle);
    int expandedNameID = _exptype(identity);

    return m_expandedNameTable.getNamespaceID(expandedNameID);
  }

  /**
   * Given a node handle, return its DOM-style node name. This will
   * include names such as #text or #document.
   *
   * @param nodeHandle the id of the node.
   * @return String Name of this node, which may be an empty string. %REVIEW% Document when empty
   * string is possible... %REVIEW-COMMENT% It should never be empty, should it?
   */
  public abstract String getNodeName(int nodeHandle);

  /**
   * Given a node handle, return the XPath node name.  This should be
   * the name as described by the XPath data model, NOT the DOM-style
   * name.
   *
   * @param nodeHandle the id of the node.
   * @return String Name of this node, which may be an empty string.
   */
  public String getNodeNameX(int nodeHandle) {

    /** @todo: implement this com.sun.org.apache.xml.internal.dtm.DTMDefaultBase abstract method */
    error(XMLMessages
        .createXMLMessage(XMLErrorResources.ER_METHOD_NOT_SUPPORTED, null));//"Not yet supported!");

    return null;
  }

  /**
   * Given a node handle, return its XPath-style localname.
   * (As defined in Namespaces, this is the portion of the name after any
   * colon character).
   *
   * @param nodeHandle the id of the node.
   * @return String Local name of this node.
   */
  public abstract String getLocalName(int nodeHandle);

  /**
   * Given a namespace handle, return the prefix that the namespace decl is
   * mapping.
   * Given a node handle, return the prefix used to map to the namespace.
   *
   * <p> %REVIEW% Are you sure you want "" for no prefix?  </p>
   * <p> %REVIEW-COMMENT% I think so... not totally sure. -sb  </p>
   *
   * @param nodeHandle the id of the node.
   * @return String prefix of this node's name, or "" if no explicit namespace prefix was given.
   */
  public abstract String getPrefix(int nodeHandle);

  /**
   * Given a node handle, return its DOM-style namespace URI
   * (As defined in Namespaces, this is the declared URI which this node's
   * prefix -- or default in lieu thereof -- was mapped to.)
   *
   * <p>%REVIEW% Null or ""? -sb</p>
   *
   * @param nodeHandle the id of the node.
   * @return String URI value of this node's namespace, or null if no namespace was resolved.
   */
  public abstract String getNamespaceURI(int nodeHandle);

  /**
   * Given a node handle, return its node value. This is mostly
   * as defined by the DOM, but may ignore some conveniences.
   * <p>
   *
   * @param nodeHandle The node id.
   * @return String Value of this node, or null if not meaningful for this node type.
   */
  public abstract String getNodeValue(int nodeHandle);

  /**
   * Given a node handle, return its DOM-style node type.
   * <p>
   * %REVIEW% Generally, returning short is false economy. Return int?
   * %REVIEW% Make assumption that node has already arrived.  Is OK?
   *
   * @param nodeHandle The node id.
   * @return int Node type, as per the DOM's Node._NODE constants.
   */
  public short getNodeType(int nodeHandle) {
    if (nodeHandle == DTM.NULL) {
      return DTM.NULL;
    }
    return m_expandedNameTable.getType(_exptype(makeNodeIdentity(nodeHandle)));
  }

  /**
   * Get the depth level of this node in the tree (equals 1 for
   * a parentless node).
   *
   * @param nodeHandle The node id.
   * @return the number of ancestors, plus one
   * @xsl.usage internal
   */
  public short getLevel(int nodeHandle) {
    // Apparently, the axis walker stuff requires levels to count from 1.
    int identity = makeNodeIdentity(nodeHandle);
    return (short) (_level(identity) + 1);
  }

  /**
   * Get the identity of this node in the tree
   *
   * @param nodeHandle The node handle.
   * @return the node identity
   * @xsl.usage internal
   */
  public int getNodeIdent(int nodeHandle) {
    /*if (nodeHandle != DTM.NULL)
      return nodeHandle & m_mask;
    else
      return DTM.NULL;*/

    return makeNodeIdentity(nodeHandle);
  }

  /**
   * Get the handle of this node in the tree
   *
   * @param nodeId The node identity.
   * @return the node handle
   * @xsl.usage internal
   */
  public int getNodeHandle(int nodeId) {
    /*if (nodeId != DTM.NULL)
      return nodeId | m_dtmIdent;
    else
      return DTM.NULL;*/

    return makeNodeHandle(nodeId);
  }

  // ============== Document query functions ==============

  /**
   * Tests whether DTM DOM implementation implements a specific feature and
   * that feature is supported by this node.
   *
   * @param feature The name of the feature to test.
   * @param version This is the version number of the feature to test. If the version is not
   * specified, supporting any version of the feature will cause the method to return
   * <code>true</code>.
   * @return Returns <code>true</code> if the specified feature is supported on this node,
   * <code>false</code> otherwise.
   */
  public boolean isSupported(String feature, String version) {

    // %TBD%
    return false;
  }

  /**
   * Return the base URI of the document entity. If it is not known
   * (because the document was parsed from a socket connection or from
   * standard input, for example), the value of this property is unknown.
   *
   * @return the document base URI String object or null if unknown.
   */
  public String getDocumentBaseURI() {
    return m_documentBaseURI;
  }

  /**
   * Set the base URI of the document entity.
   *
   * @param baseURI the document base URI String object or null if unknown.
   */
  public void setDocumentBaseURI(String baseURI) {
    m_documentBaseURI = baseURI;
  }

  /**
   * Return the system identifier of the document entity. If
   * it is not known, the value of this property is unknown.
   *
   * @param nodeHandle The node id, which can be any valid node handle.
   * @return the system identifier String object or null if unknown.
   */
  public String getDocumentSystemIdentifier(int nodeHandle) {

    // %REVIEW%  OK? -sb
    return m_documentBaseURI;
  }

  /**
   * Return the name of the character encoding scheme
   * in which the document entity is expressed.
   *
   * @param nodeHandle The node id, which can be any valid node handle.
   * @return the document encoding String object.
   * @xsl.usage internal
   */
  public String getDocumentEncoding(int nodeHandle) {

    // %REVIEW%  OK??  -sb
    return "UTF-8";
  }

  /**
   * Return an indication of the standalone status of the document,
   * either "yes" or "no". This property is derived from the optional
   * standalone document declaration in the XML declaration at the
   * beginning of the document entity, and has no value if there is no
   * standalone document declaration.
   *
   * @param nodeHandle The node id, which can be any valid node handle.
   * @return the document standalone String object, either "yes", "no", or null.
   */
  public String getDocumentStandalone(int nodeHandle) {
    return null;
  }

  /**
   * Return a string representing the XML version of the document. This
   * property is derived from the XML declaration optionally present at the
   * beginning of the document entity, and has no value if there is no XML
   * declaration.
   *
   * @param documentHandle The document handle
   * @return the document version String object.
   */
  public String getDocumentVersion(int documentHandle) {
    return null;
  }

  /**
   * Return an indication of
   * whether the processor has read the complete DTD. Its value is a
   * boolean. If it is false, then certain properties (indicated in their
   * descriptions below) may be unknown. If it is true, those properties
   * are never unknown.
   *
   * @return <code>true</code> if all declarations were processed; <code>false</code> otherwise.
   */
  public boolean getDocumentAllDeclarationsProcessed() {

    // %REVIEW% OK?
    return true;
  }

  /**
   * A document type declaration information item has the following properties:
   *
   * 1. [system identifier] The system identifier of the external subset, if
   * it exists. Otherwise this property has no value.
   *
   * @return the system identifier String object, or null if there is none.
   */
  public abstract String getDocumentTypeDeclarationSystemIdentifier();

  /**
   * Return the public identifier of the external subset,
   * normalized as described in 4.2.2 External Entities [XML]. If there is
   * no external subset or if it has no public identifier, this property
   * has no value.
   *
   * @return the public identifier String object, or null if there is none.
   */
  public abstract String getDocumentTypeDeclarationPublicIdentifier();

  /**
   * Returns the <code>Element</code> whose <code>ID</code> is given by
   * <code>elementId</code>. If no such element exists, returns
   * <code>DTM.NULL</code>. Behavior is not defined if more than one element
   * has this <code>ID</code>. Attributes (including those
   * with the name "ID") are not of type ID unless so defined by DTD/Schema
   * information available to the DTM implementation.
   * Implementations that do not know whether attributes are of type ID or
   * not are expected to return <code>DTM.NULL</code>.
   *
   * <p>%REVIEW% Presumably IDs are still scoped to a single document,
   * and this operation searches only within a single document, right?
   * Wouldn't want collisions between DTMs in the same process.</p>
   *
   * @param elementId The unique <code>id</code> value for an element.
   * @return The handle of the matching element.
   */
  public abstract int getElementById(String elementId);

  /**
   * The getUnparsedEntityURI function returns the URI of the unparsed
   * entity with the specified name in the same document as the context
   * node (see [3.3 Unparsed Entities]). It returns the empty string if
   * there is no such entity.
   * <p>
   * XML processors may choose to use the System Identifier (if one
   * is provided) to resolve the entity, rather than the URI in the
   * Public Identifier. The details are dependent on the processor, and
   * we would have to support some form of plug-in resolver to handle
   * this properly. Currently, we simply return the System Identifier if
   * present, and hope that it a usable URI or that our caller can
   * map it to one.
   * TODO: Resolve Public Identifiers... or consider changing function name.
   * <p>
   * If we find a relative URI
   * reference, XML expects it to be resolved in terms of the base URI
   * of the document. The DOM doesn't do that for us, and it isn't
   * entirely clear whether that should be done here; currently that's
   * pushed up to a higher level of our application. (Note that DOM Level
   * 1 didn't store the document's base URI.)
   * TODO: Consider resolving Relative URIs.
   * <p>
   * (The DOM's statement that "An XML processor may choose to
   * completely expand entities before the structure model is passed
   * to the DOM" refers only to parsed entities, not unparsed, and hence
   * doesn't affect this function.)
   *
   * @param name A string containing the Entity Name of the unparsed entity.
   * @return String containing the URI of the Unparsed Entity, or an empty string if no such entity
   * exists.
   */
  public abstract String getUnparsedEntityURI(String name);

  // ============== Boolean methods ================

  /**
   * Return true if the xsl:strip-space or xsl:preserve-space was processed
   * during construction of the DTM document.
   *
   * @return true if this DTM supports prestripping.
   */
  public boolean supportsPreStripping() {
    return true;
  }

  /**
   * Figure out whether nodeHandle2 should be considered as being later
   * in the document than nodeHandle1, in Document Order as defined
   * by the XPath model. This may not agree with the ordering defined
   * by other XML applications.
   * <p>
   * There are some cases where ordering isn't defined, and neither are
   * the results of this function -- though we'll generally return false.
   *
   * @param nodeHandle1 Node handle to perform position comparison on.
   * @param nodeHandle2 Second Node handle to perform position comparison on .
   * @return true if node1 comes before node2, otherwise return false. You can think of this as
   * <code>(node1.documentOrderPosition &lt;= node2.documentOrderPosition)</code>.
   */
  public boolean isNodeAfter(int nodeHandle1, int nodeHandle2) {
    // These return NULL if the node doesn't belong to this document.
    int index1 = makeNodeIdentity(nodeHandle1);
    int index2 = makeNodeIdentity(nodeHandle2);

    return index1 != NULL && index2 != NULL && index1 <= index2;
  }

  /**
   * 2. [element content whitespace] A boolean indicating whether the
   * character is white space appearing within element content (see [XML],
   * 2.10 "White Space Handling"). Note that validating XML processors are
   * required by XML 1.0 to provide this information. If there is no
   * declaration for the containing element, this property has no value for
   * white space characters. If no declaration has been read, but the [all
   * declarations processed] property of the document information item is
   * false (so there may be an unread declaration), then the value of this
   * property is unknown for white space characters. It is always false for
   * characters that are not white space.
   *
   * @param nodeHandle the node ID.
   * @return <code>true</code> if the character data is whitespace; <code>false</code> otherwise.
   */
  public boolean isCharacterElementContentWhitespace(int nodeHandle) {

    // %TBD%
    return false;
  }

  /**
   * 10. [all declarations processed] This property is not strictly speaking
   * part of the infoset of the document. Rather it is an indication of
   * whether the processor has read the complete DTD. Its value is a
   * boolean. If it is false, then certain properties (indicated in their
   * descriptions below) may be unknown. If it is true, those properties
   * are never unknown.
   *
   * @param documentHandle A node handle that must identify a document.
   * @return <code>true</code> if all declarations were processed; <code>false</code> otherwise.
   */
  public boolean isDocumentAllDeclarationsProcessed(int documentHandle) {
    return true;
  }

  /**
   * 5. [specified] A flag indicating whether this attribute was actually
   * specified in the start-tag of its element, or was defaulted from the
   * DTD.
   *
   * @param attributeHandle The attribute handle in question.
   * @return <code>true</code> if the attribute was specified; <code>false</code> if it was
   * defaulted.
   */
  public abstract boolean isAttributeSpecified(int attributeHandle);

  // ========== Direct SAX Dispatch, for optimization purposes ========

  /**
   * Directly call the
   * characters method on the passed ContentHandler for the
   * string-value of the given node (see http://www.w3.org/TR/xpath#data-model
   * for the definition of a node's string-value). Multiple calls to the
   * ContentHandler's characters methods may well occur for a single call to
   * this method.
   *
   * @param nodeHandle The node ID.
   * @param ch A non-null reference to a ContentHandler.
   * @param normalize true if the content should be normalized according to the rules for the XPath
   * <a href="http://www.w3.org/TR/xpath#function-normalize-space">normalize-space</a> function.
   */
  public abstract void dispatchCharactersEvents(
      int nodeHandle, org.xml.sax.ContentHandler ch, boolean normalize)
      throws org.xml.sax.SAXException;

  /**
   * Directly create SAX parser events from a subtree.
   *
   * @param nodeHandle The node ID.
   * @param ch A non-null reference to a ContentHandler.
   */
  public abstract void dispatchToEvents(
      int nodeHandle, org.xml.sax.ContentHandler ch)
      throws org.xml.sax.SAXException;

  /**
   * Return an DOM node for the given node.
   *
   * @param nodeHandle The node ID.
   * @return A node representation of the DTM node.
   */
  public org.w3c.dom.Node getNode(int nodeHandle) {
    return new DTMNodeProxy(this, nodeHandle);
  }

  // ==== Construction methods (may not be supported by some implementations!) =====

  /**
   * Append a child to the end of the document. Please note that the node
   * is always cloned if it is owned by another document.
   *
   * <p>%REVIEW% "End of the document" needs to be defined more clearly.
   * Does it become the last child of the Document? Of the root element?</p>
   *
   * @param newChild Must be a valid new node handle.
   * @param clone true if the child should be cloned into the document.
   * @param cloneDepth if the clone argument is true, specifies that the clone should include all
   * it's children.
   */
  public void appendChild(int newChild, boolean clone, boolean cloneDepth) {
    error(XMLMessages.createXMLMessage(XMLErrorResources.ER_METHOD_NOT_SUPPORTED,
        null));//"appendChild not yet supported!");
  }

  /**
   * Append a text node child that will be constructed from a string,
   * to the end of the document.
   *
   * <p>%REVIEW% "End of the document" needs to be defined more clearly.
   * Does it become the last child of the Document? Of the root element?</p>
   *
   * @param str Non-null reverence to a string.
   */
  public void appendTextChild(String str) {
    error(XMLMessages.createXMLMessage(XMLErrorResources.ER_METHOD_NOT_SUPPORTED,
        null));//"appendTextChild not yet supported!");
  }

  /**
   * Simple error for asserts and the like.
   *
   * @param msg Error message to report.
   */
  protected void error(String msg) {
    throw new DTMException(msg);
  }

  /**
   * Find out whether or not to strip whispace nodes.
   *
   * @return whether or not to strip whispace nodes.
   */
  protected boolean getShouldStripWhitespace() {
    return m_shouldStripWS;
  }

  /**
   * Set whether to strip whitespaces and push in current value of
   * m_shouldStripWS in m_shouldStripWhitespaceStack.
   *
   * @param shouldStrip Flag indicating whether to strip whitespace nodes
   */
  protected void pushShouldStripWhitespace(boolean shouldStrip) {

    m_shouldStripWS = shouldStrip;

    if (null != m_shouldStripWhitespaceStack) {
      m_shouldStripWhitespaceStack.push(shouldStrip);
    }
  }

  /**
   * Set whether to strip whitespaces at this point by popping out
   * m_shouldStripWhitespaceStack.
   */
  protected void popShouldStripWhitespace() {
    if (null != m_shouldStripWhitespaceStack) {
      m_shouldStripWS = m_shouldStripWhitespaceStack.popAndTop();
    }
  }

  /**
   * Set whether to strip whitespaces and set the top of the stack to
   * the current value of m_shouldStripWS.
   *
   * @param shouldStrip Flag indicating whether to strip whitespace nodes
   */
  protected void setShouldStripWhitespace(boolean shouldStrip) {

    m_shouldStripWS = shouldStrip;

    if (null != m_shouldStripWhitespaceStack) {
      m_shouldStripWhitespaceStack.setTop(shouldStrip);
    }
  }

  /**
   * A dummy routine to satisify the abstract interface. If the DTM
   * implememtation that extends the default base requires notification
   * of registration, they can override this method.
   */
  public void documentRegistration() {
  }

  /**
   * A dummy routine to satisify the abstract interface. If the DTM
   * implememtation that extends the default base requires notification
   * when the document is being released, they can override this method
   */
  public void documentRelease() {
  }

  /**
   * Migrate a DTM built with an old DTMManager to a new DTMManager.
   * After the migration, the new DTMManager will treat the DTM as
   * one that is built by itself.
   * This is used to support DTM sharing between multiple transformations.
   *
   * @param mgr the DTMManager
   */
  public void migrateTo(DTMManager mgr) {
    m_mgr = mgr;
    if (mgr instanceof DTMManagerDefault) {
      m_mgrDefault = (DTMManagerDefault) mgr;
    }
  }

  /**
   * Query which DTMManager this DTM is currently being handled by.
   *
   * %REVEW% Should this become part of the base DTM API?
   *
   * @return a DTMManager, or null if this is a "stand-alone" DTM.
   */
  public DTMManager getManager() {
    return m_mgr;
  }

  /**
   * Query which DTMIDs this DTM is currently using within the DTMManager.
   *
   * %REVEW% Should this become part of the base DTM API?
   *
   * @return an IntVector, or null if this is a "stand-alone" DTM.
   */
  public SuballocatedIntVector getDTMIDs() {
    if (m_mgr == null) {
      return null;
    }
    return m_dtmIdent;
  }
}
